小型船舶軌跡控制測試及GIS整合討論

A Study on Small Boat-Based Track-Keeping Control Experiments and GIS Integration

本文以內模式控制IMC（Internal Model Control）設計法，針對Nomoto船舶模式進行航向控制自航器設計，再以PID控制器架構實現之。經由結合高精度即時動態RTK（Real Time Kinematics） GPS定位，並運用所提出之修正四象限導航律計算參考航向角，經由一序列之航向變換控制，進行軌跡追蹤之任務，成功達成船舶自動操縱控制之目的。於此透過NavCOM生產之NCT-2000D GPS接收機、Pacific Crest所生產無線電資料傳輸設備PDL（Positioning Data Link）及電子羅盤TCM2等系統整合，以提供實驗船舶位置、艏向資訊作為導航及控制計算依據。實驗介面乃使用研華公司之ADAM 4000系列模組作為類比／數位訊號轉換器，且運用線性電阻尺為舵機舵角之迴授訊號，於海洋大學小艇碼頭進行小型船實驗測試。本研究先經由電腦模擬，找出可行之控制器增益參數，並發現該增益值可以直接引用於實船測試，因而大幅節省實驗需求時間。本文順利完成航向控制及軌跡控制之任務，並於航行過程蒐集位置、航向、橫搖、水深、風向／風速等環境及本船資料，建構一小型地理資訊系統架構。本研究所建構之系統，除可供作不同自航器設計法之測試平台，亦提供一經濟且便於操作的港域水文資料調查平台。 A small boat-based GIS (Geographical Information System) and track-keeping system is proposed in this work Specifically, the IMC (Internal Model Control) method is used in the autopilot design, and the controller is implemented in the PID structure The track-keeping mission is achieved through a sequence of course-keeping maneuvers to reach the preselected waypoints. A simplified 4-quadrant guidance law is developed that employs the ownship position and the target waypoint in computing the reference heading needed in the course-keeping loop Several instruments are used in the experimental studies Specifically, the high precision NCT-2000D RTK GPS receiver made by NavCom, the electronic compass, the ADAM 4000 A/D D/A modules and two outboard steering engines are installed in the small boat. Simulations for course-keeping and track-keeping are first carried out to examine the feasibility of the proposed approach. Then the small boat-based experiments are conducted in the small boat harbour near the National Taiwan Ocean University to further validate the performance of the proposed guidance and control law. The feasible controller gain values found in the computer simulations are readily applicable in the field tests. Consequently, the time spent on the small boat-based experiments is significantly reduced. Satisfactory course-keeping and up to 10 waypoints track-keeping experimental results are achieved. The data collected with the onboard sensors are integrated in forming the small boat-based GIS platform that may serve as a cost-effective harbour waterway surveying system.